, 9, 13, 37, 0)
    >>> delta = relativedelta(hours=25, day=1, weekday=MO(1))
    >>> dt + delta
    datetime.datetime(2018, 4, 2, 14, 37)

    First, the day is set to 1 (the first of the month), then 25 hours
    are added, to get to the 2nd day and 14th hour, finally the
    weekday is applied, but since the 2nd is already a Monday there is
    no effect.

    Nr